I'm trying to do data mining on a web log which recorded one day web access information from a busy web server. I imported the data into Oracle Data miner, and created a table (WEBLOG). The idea is to create a new field, i.e. session, for the users so that each session could be thought as a representative of a user-intent (aka topic). Now based on this, data mining models would be used to cluster(group) the users based on their similarity. The first step is to prepare the data which involves using SQL queries. So first, all I did was to create a function for date and time. This is the following code I used,

Error starting at line 1 in command:
create table FINAL_LOG as
select SESSION_DT, C_IP, CS_USER_AGENT,
listagg(WEB_LINK, ' ')
within group(order by C_IP, CS_USER_AGENT) "WEB_LINKS"
from WEBLOG_VIEWS
group by C_IP, CS_USER_AGENT, SESSION_DT
order by SESSION_DT
Error at Command Line:1 Column:7
Error report:
SQL Error: ORA-01861: literal does not match format string
ORA-06512: at "DMUSER.SSNDATE", line 11
ORA-06512: at line 1
01861. 00000 - "literal does not match format string"
*Cause: Literals in the input must be the same length as literals in
the format string (with the exception of leading whitespace).
If the "FX" modifier has been toggled on, the literal must
match exactly, with no extra whitespace.
*Action: Correct the format string to match the literal.

I don't know where I'm going wrong with this.. the to_date function should be fine. In the data that I possess, the date and time are in no format. Example: 30118 and 0:00:09 respectively. If anyone has any clue about this I would be sincerely grateful for any help that I can get!! It's quite urgent..